Counter-current pulp conditioner



NOV- 26, 1963 L. E. EBERHARDT COUNTER-CURRENT PULP CONDITIONER Filed March l2, 1962 #fraz/vir United States Patent O 3,111,832 COUNTER-CURRENT PULP CONDITEUNER Lee E. Eberhardt, Springfield, Ohio, assigner to The Bauer Bros. Co., Springfield, Ohio, a corporation of Ghio Filed Mar. 12, 1962, Ser. No. 178,974 12 Claims. (Cl. 68-143) This invention relates to a novel means for conditioning pulp.

Pulp must be conditioned by various agents during a refining process. There are agents which facilitate defiberiz-ation, bleaching agents which increase brightness and enhance pulp quality, and washing agents which must be applied to remove residuals of other agents or pulp constituents extracted in the refining process. Each agent serves a useful purpose and the effectiveness of its application has a direct bearing on the end product. Since pulp is processed in a liuid medium, these agents are generally injected in a fluid form.

The present invention is directed :to improvements in available means for applying these agents.

A primary object of the invention is to provide a system for conditioning pulp which is economical, more eiiicient and satisfactory in use, and adaptable to a wide variety of applications.

Another object of the invention is to provide apparatus enabling an improved pulp conditioning process.

A further object of the invention is to provide a pulp conditioning system afford-ing a counter-current application of conditioning agents to pulp flowing in a refining process.

An additional object of the invention is to provide an improved apparatus for conditioning pulp.

Another object of the invention is to provide a novel pulp conditioning apparatus wherein conditioning media are injected at successive stages counter to fthe normal pulp flow.

A further object of the invention is to provide a countercurrent washing system particularly applicable for use in a pulp refining process.

Another object of fthe invention is to provide a pulp conditioning system enabling a more effective application of conditioning agents.

Another object of the invention is to provide an improved system for conditioning pulp possessing the advantageous structural features, the inherent meritorious characteristics and the means and mode of operation herein described. i

With the above and other incidental objects in View as will more fully appear in the specification, the invention intended to be protected by Letters Patent consists of the features of construction, the parts and combinations thereof, and the mode of operation as hereinafter described or illustrated in fthe accompanying drawings, or their equivalents.

Referring to the accompanying drawing wherein is shown one but obviously not necessarily the only form of embodiment of the invention. l

The sole FIGURE schematically illustrates a pulp conditioning system in accondance with the invention.

The invention will be described with reference to the washing of pulp during a refining process. However, as mentioned previously, its application is not so limited.

Viewing the drawing, the illustrated system provides for the movement of pulp from a refining phase through a hopper 1 and screw type feeder 2 to be discharged by gravity flow through the inlet 3 of a vessel 4.

The vessel 4 has a generally tubular configuration and a vertical inclination with its inlet uppermost. =It is hollow and closed fto either end by a liemi-spherical cap 5. A hollow partition 6 provides a diametral bridge sub- 3,1 l l,832 Patented Nov. 26, 1963 ICC stantially the length of the vessel 4, terminating to either end short of the hemisphe-rical cavities 7 which are defined by the caps 5. Nested at the lowermost end of the partition 6, coextensive therewith, is a shaft 37. The shaft 37 provides a pivot for a pair of laterally spaced parallel sprockets 8. Tlhe shaft 37 lies on a major diameter of the lower :cap 5 and the adjacent end of the partition is suitably recessed to accommodate rotation of the sprockets. A shaft 9 bridges the upper end of the vessel 4 to lie parallel to the shaft 37 on a major diameter of the upper cap 5. The shaft 9 mounts parallel sprockets 10, respectively co-planar with one of the sprockets 8 to which it drivingly relates by a continuous sprocket chain 11. The chains 11 are transversely connected at equidistantly spaced points by pins 12 which swingably mount parallel pusher blades 13.

The partition 6 thus divides the vessel 4 into hernicylindrical sections 14 and 15. The sections 14 and 15 respectively lie adjacent the upper and lower sides of the partition and connect to either end through the hemisphenical cavities 7. A continuous passage is thus provided to lead from the inlet 3 and passage section 14 to the lower cavity 7 and up through the passage Section 15 to a dependent tube 16 defining an outlet at its upper extremity.

Ilnlets 17 and 1S are spaced on the upper surface of vessel 4 Ito :connect into the passage Section 14 respectively adjacent the inlet 3 and the lower cavity 7. The upper surface of partition 6 has a screened recess 19 positioned in communication with the passage section 14 between the inlets 17 and 18 and immediately preceding the inlet 13. A conduit 20 opens at one end to the recess 19 and connects at its other end to a pump 21 for purposes to be further described.

The undersurface of vessel 4 has three screened drain apertures 22, 23 and 24 opening from the passage section 15 to dependent suction boxes. The aperture 22 is positioned to immediately precede the outlet 16; the aperture 23 is located adjacent the lower cavity 7; and the aperture 24 is positioned intermediate the apertures 22 and 23.

The underside of partition `6 has a screened recess 25 accommodating the discharge nozzle 26 of a conduit leadling from a pump 27. The recess 25 is positioned immediately following the ldrain 24 in passage section 15, in advance of the outlet 16. A second screened recess 28 in the underside of partition 6 accommodates the discharge nozzle 29 of a conduit 30 leading from a pump 31. The recess 28 is positioned between the drains 23 and 24.

In the system shown, a conduit 32 connects drain 22 to the pump 31. Drain 2.4 connects through a conduit 33 to a pump 34 which in turn connects through -a conduit 35 to the inlets 18. Drain 23 also connects to a pump 36 which in turn connects through a conduit 33 to inlets 17.

The systems above Vdescribed provides what may be considered a counter-current pulp conditioner. The conditioning medium, which in this case is water, is moved through the system in a direction counter to the normal flow of pulp through the vessel 4.

It is to be understood that means are suitably connected to drive shaft 9, sprockets 10", chains 11, and thereby blades 13. On introduction of the pulp through the inlet '3, the blades 13 pick up the pulp to move it through the passage section 14, the lower cavity 7 and up through the passage section 15 to provide a continuous liow o-f the pulp to the outlet 16.

Considering the apparatus illustrated as a counter-current washer, as pulp is flowed through the vessel 4, fresh water is delivered through a conduit from the pump 27 to be injected into the flowing pulp through the nozzle 26. 'Ihe yfresh water is thus disseminated into the pulp to s,111,sa2

commence a washing action which is continuous at the station defined by the nozzle 2.6. The fresh water so injected diffuses through the pulp mixture as it moves therewith to the outlet 16. In the process the Wash water picks up undesirable liquor content entrained with the pulp. The pump 3l applies a suction at the drain 2.2 which draws the water and liquor content washed from the pulp to exit from the vessel 4 through the conduit 32.

At this stage, the Water which serves las a pulp conditioning or washing Ifluid has beenl converted to a weak liquor, havin-g entrained the chemical products of its initial washing action. The conditioning fluid in the form of this weak liquor is directed from the pump 3l through a conduit S to the nozzle 29` where it is re-injected in the pulp flowing in the vessel 4 at a position in advance of the drain 24. Thus the nozzle 29 defines a station in the passage section 15 where there is a continuous flow of this relatively Weak liquor to produce a further washing action on the pulp. As in the first instance, this conditioning fluid diffuses through the pulp mixture `as it moves therewith as far as the vdrain 24. In this movement, the relatively 'weak liquor picks up a stronger chemical content as it washes undesired ingredients Kfrom the pulp fibers. At the drain 24 a suction is applied by the pump 34 to `draw the conditioning fluid with its increased liquor content through the conduit 33. The conditioning fluid, now having a stronger liquor content, is directed by the pump 34 to -llow through a conduit 35 to the inlets 18, The conditioning fluid thus modified again serves a similar washing function, this time in a section between the inlets l@ and the drain 213. By the time the conditioning lluid moves with the pulp to the drain Z3, it has a relatively strong liquor content and is withdrawn by operation of a pump 36 and llows the-reby through a conduit 38 to the inlets l7 immediately following the vessel inlet 3. Of course, the pulp mixture has its strongest liquor content as it enters the vessel and a washing action is effected thereon by the conditioning fluid in its modified form as injected at the inlets 17. The washing action on the pulp lfibers is effected between the inlet 17 and drain 19 as the conditioning fluid diffuses through the pulp mixture. The application of the pump 2l effects the withdrawal of the conditioning fluid with an increased liquor content at the drain 19 in advance of the inlets i8. The conditioning fluid as modified moves through the conduit Z- to be discharged by the pump 21 to a liquor recovery system.

ln the system illustrated there is a continuous counterflow of the conditioning lluid through successively spaced sections of the passage through the vessel 4, ever closer to its inlet. The water which here serves as a conditioning medium piclcs up an increased liquor content as it progresses through each successive section of the system from its outlet to its inlet. The net -result is to provide an optimum use of a charge o-f conditioning fluid. Moreover, it produces a staged conditioning of the pulp which is most effective and eilicient. In this manner the pulp fibers are exposed to a maximum conditioning or Washing action so the extraction of the undesired liquors is optimum.

As mentioned previously, the system and method of the invention may be applied in many -Ways and for many purposes. Not only does the system avoid the need for complex apparatus in a conditioning procedure but it reduces the time of the conditioning procedure to a minimum and enables it to be accomplished during the normal llow of pulp through a refining process.

In summary, the invention as illustrated provides for movement of pulp through a conditioning vessel, the introduction of a conditioning agent in an uncontaminated form to diffuse through the pulp during a period immediately preceding its discharge from the vessel, the lagent being slightly contaminated by its action on the pulp, and the agent thus Contaminated being withdrawn and successively circulated through sections of the vessel, ever closer to its inlet. The conditioning agent is additionally contaminated in each successive circulation through a section of the vessel until it is finally discharged to a recovery system as described. Correspondingly, in the washing action described, the pulp which has its highest liquor content on entrance to the vessel 4 is successively subjected to the action of Ithe conditioning or washing agent in a sucessively less contaminated form. In this -way there is a staged conditioning or washing action with the pulp reaching a weak liquor content immediately preceding the outlet, where it is finally washed or -conditioned by the conditioning agent in its uncontaminated form. The apparatus and process thus provided is highly effective.

From the above description it will be apparent that there is thus provided a device of the `character described possessing the particular features of advantage before enumerated as desirable, but which obviously is susceptible of modification in its form, proportions, detail construction and arrangement of parts without departing from the principle involved or sacrificing any of its advantages.

While in order to comply with the statute the invention has been ydescribed in language more or less specific as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein disclosed comprise but one of several modes of putting the invention into effect, and the invention is therefore claimed in any of its forms or modifications within the legitimate and valid scope of the appended claims.

I claim:

l. A pulp conditioning system comprising, means including a partition defining a chamber having an inlet and an outlet and a passage therebetween, means for moving pulp in a fluid state through said passage from said inlet to said outlet, means connected in said partition adjacent and spaced from said outlet for injecting a .conditioning fluid in said passage, said passage being formed to cause the conditioning fluid to Allow with the pulp and diffuse therethrough in transit, means connected into said passage immediately pre-ceding said outlet for extracting the conditioning fluid in a form modified by its action on `the pulp and reinjecting in said passage the lluid so modified for similar movement with and further action on the pulp in a section of said passage closer to said inlet.

2. A pulp 4conditioning system including, means defining an elongated chamber having an inlet, an outlet and a dividing mid-partition, at least one of the extremities of said partition being short of an extremity of said chamber to provide for a continuous passage about said partition between said inlet and outlet, means mounted to move about said partition to carry pulp from said inlet to said outlet, means defining a fluid .drain in said partition to the side thereof adjacent said inlet, means connected to inject a pulp modifying lfluid into said chamber to the side of said partition adjacent said outlet, said `chamber and mid-partition being formed to cause said fluid to flow with, diffuse through, and condition the pulp in movement to said outlet and means for extracting the conditioning fluid in a form as modified by the conditioning process immediately adjacent said outlet and reinjecting it in said chamber at positions successively closer to said inlet for eventual `discharge through said drain.

3. In a vessel providing a pulp conditioning chamber, means `defining an extended passage therethrough, means defining inlets and outlets, at least a portion of which are located interiorly of said chamber, spaced longitudinally of said passage to divide said passage into immediately successive conditioning sections and means connected to said inlets and outlets for cycling a charge of pulp conditioning fluid successively through each such section, the length thereof.

4. The structure as set forth in claim 3 characterized by said cycling means being operative in a direction counter to the normal tlow of pulp through said passage.

5. A pulp conditioning system, including means defining a chamber having a pulp inlet and longitudinally spaced therefrom a pulp outlet, a passage formed in said chamber which interconnects said inlet and outlet, means for moving pulp through said passage, and means dening a plurality of uid inlets and fluid outlets opening into said passage, at least a portion of which are located in the interior of said chamber, said fluid inlets and fluid outlets being arranged in longitudinally spaced alternating relation to one another to divide said passage into a continuous series of conditioning sections, said passage being formed to cause pulp conditioning iluid injected through said inlets to be constrained to move with pulp therein to the immediately following fluid outlet, said fluid outlets being connected to supply selected fluid inlets.

6. A pulp conditioning system including means defining a chamber having a pulp inlet and longitudinally spaced therefrom a pulp outlet, a partition in said chamber forming a passage which interconnects said inlet and outlet, means for moving pulp through said passage, a plurality of iluid inlets and ilu-id outlets in said chamber and said partition opening into said passage in longitudinally spaced alternating relation to one another to divide said passage into a continuous series of conditioning sections, said passage being formed to cause pulp conditioning fluid injected through said inlets to be constrained to move with the pulp therein to the immediately lfollowing fluid outlet and said iiuid outlets being connected to supply selected fluid inlets.

7. A pulp conditioning system, including a chamber having a pulp inlet and longitudinally spaced therefrom a pulp outlet and an interconnecting passage therebetween, means for moving pulp through said passage, means deiining a plurality of fluid inlets communicating with said passage, at least a portion of which is located in the interior of said chamber, said fluid inlets communicating with said passage at locations spaced longitudinally of one another between said pulp inlet and said pulp outlet and a plurality of fluid outlets, at least a portion of which is located in the interior of said chamber, communicating with said passage at locations spaced longitudinally of one another and in alternating relation to the locations of said fluid inlets, said passage being formed to provide a continuous movement or" the fluid flowing from each fluid inlet to an adjacent uid outlet in contacting relation to the moving pulp therein.

`8. A pulp con-ditioning system including a chamber having a pulp inlet and longitudinally spaced therefrom a pulp outlet and a partition forming an interconnecting passage therebetween, means for moving pulp through said passage, a plurality of iiuid inlets, at least a portion of which is located in said partition, communicating with said passage at locations spaced longitudinally of one another between said pulp inlet and said pulp outlet and a plurality of uid outlets, at least a portion of which is located in said partition, communicating with said passage at locations spaced longitudinally of one another and in alternating relation to the locations of said fluid inlets, said passage being formed to provide a continuous movement of the iluid flowing from each duid inlet to an adjacent fluid outlet in contacting relation to the moving pulp therein.

9. A pulp conditioning system, including a vessel having a pulp inlet and a pulp outlet and an interconnecting passage of longitudinal extent, means for moving pulp through said passage, a iluid inlet communicating with said passage intermediate said pulp inlet and said pulp outlet, a iiuid outlet communicating with said passage at a location longitudinally spaced from said iiuid inlet toward `said pulp outlet, the uid from said iluid inlet utilizing a longitudinal portion of said passage, said portion of said passage being formed to cause the fluid to flow with the pulp therein to said uid outlet, a second fluid inlet communicating with said passage at a location between said pulp inlet land the rst said uid inlet, a second fluid outlet communicating with said passage at a location between said second fluid inlet and the lirst said fluid inlet and longitudinally spaced from said second fluid inlet, said second uid inlet being supplied with fluid from the first said fluid outlet and -a portion of said uid inlets and youtlets being deiined by means located in the interior of said vessel and in communication with said passage.

l0. A pulp conditioning system, including an elongated vessel having general-ly opposed pulp inlet and pulp outlet openings at one end thereof, -a partition intermediately disposed in said vessel defining a circuitous passage between said pulp inlet opening and said pulp outlet opening, the opposite end of said vessel forming a turnaround area, means for moving pulp through said passage, and `an arrangement of duid inlets and uid outlets communicating with said passage directing uid to ow with `the pulp through separate successive segments of said passage the length thereof.

ll. A pulp conditioning system according to claim 10, characterized in that said last named means includes a iiuid inlet and a uid outlet on opposite sides of said partition near said turn-around area, said passage being formed to cause fluid from said tluid inlet to ilow with the pulp through said area to said fluid outlet.

12. A pulp conditioning system including a chamber having a pulp inlet and a pulp outlet and an intercom necting passage, a plurality of fluid inlets and fluid outlets, at least a portion of which are defined by means located in the interior of said chamber, communicating with said passage at locations longitudinally spaced and alternating with one another, and means connecting said uid inlets and said fluid outlets in a iiuid flowing circuit, directing iiuid to ow with the pulp through successive relatively short segments of said passage, the length thereof, in inverse order from said pulp outlet to said pulp inlet.

References Cited in the file of this patent UNITED STATES PATENTS 394,191 Lorimer Dec. 11, 1888 412,258 Hoyt Oct. 8, 1889 1,468,337 Winestock Sept. 18, 1923 1,933,609 Wagner Nov. 7, 1933 

3. IN A VESSEL PROVIDING A PULP CONDITIONING CHAMBER, MEANS DEFINING AN EXTENDED PASSAGE THERETHROUGH, MEANS DEFINING INLETS AND OUTLETS, AT LEAST A PORTION OF WHICH ARE LOCATED INTERIORLY OF SAID CHAMBER, SPACED LONGITUDINALLY OF SAID PASSAGE TO DIVIDE SAID PASSAGE INTO IMMEDIATELY SUCCESSIVE CONDITIONING SECTIONS AND MEANS CONNECTED TO SAID INLETS AND OUTLETS FOR CYCLING A CHARGE OF PULP CONDITIONING FLUID SUCCESSIVELY THROUGH EACH SUCH SECTION, THE LENGTH THEREOF. 